Status of Cassava cultivation in Jaffna peninsula and detection of Cassava mosaic disease causing agent

Abstract

Cassava is one of the well-known vegetable crops throughout the world and the starchy tubers are used to prepare variety of food items. In Jaffna peninsula, cassava cultivation has been threatened by a disease which commonly caused by a plant virus called cassava mosaic virus. In the present study a survey was carried out to find out current knowledge and experience of farmers about cassava cultivation and cassava mosaic disease. The total DNA isolated from the infected plants was subjected to polymerase chain reaction with begomovirus specific primers to confirm the causative agent of the disease. Furthermore, controlled field experiments were carried out to confirm yield loss in different growth conditions. The survey revealed several aspects of cassava cultivation in Jaffna peninsula. In last five years the cassava crops had been continuously affected by cassava mosaic disease and that was the major factor for the reduced yield in cassava cultivation. Many of the farmers did not aware about cassava mosaic disease and effective disease management. Repeated cultivation of susceptible varieties and using infected stem-cuttings are the major reasons for the wide spread of the disease. Polymerase chain reactions have confirmed presence of begomovirus in symptomatic plants. Field experiments have revealed the spread of the pathogen through infected stem-cuttings and whitefly vectors, and confirmed the yield loss. In conclusion, cassava cultivation has been threatened by cassava mosaic disease in Jaffna peninsula, and there is an urgent need to give proper guidance to farmers to manage the disease.